Potterton Performa 24i HE Installation And Service Instructions Manual page 45

15.0 FAULT FINDING
Central Heating - Follow operational sequence (Continued)
Continued from
previous page
Does the burner remain lit ?
NO
CH temperature higher
than set point of CH
thermostat control. When
CH temperature decreases
cycle continues.
Fan runs at max speed.
YES
Air pressure switch proved.
YES
Spark at ignition electrodes
for up to 10 seconds.
YES
neon illuminated
YES
Burner extinguishes after
10 seconds.
NO
Burner output modulates
until set temperature is
reached.
YES
Burner goes out.
Publication No. 5111813
NO
neon flashing
NO
neon flashing
Go to section 'E'.
NO
neon flashing
NO
Go to section 'F'.
YES
neon flashing
Go to section 'I'
NO
Go to section 'G'.
YES
Fan stops.
Turn the selector to reset.
If regular resetting is
YES
required or appliance still
does not operate
investigation is necessary.
NO
neons flashing
Go to section 'D'.
YES
NO
Change main PCB.
Pump continues to run
YES
for 3 minutes.
(room thermostat open)
Go to section 'J'.
Turn selector to the reset
position. If the neon does
not extinguish go to
sections H and K.
YES
Operation
sequence correct
45